Data transmission in a telecommunication conference

ABSTRACT

A communication terminal into which communication data can be input and which can receive a message signalling that at least one further communication terminal is ready to receive the communication data. Following receipt of the message, a transmission device configured to operate in a first mode, in which it sends data at a first data rate, and in a second mode, in which it sends data at a second data rate, which is higher than the first data rate, is used to send the communication data in the second mode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. patent application Ser. No.11/755,888, which was filed on Jul. 11, 2007, which claims priority toProvisional Patent Application Ser. No. 60/807,043, which was filed Jul.11, 2006, and German Patent Application No. 10 2006 032 088.3, filedJul. 11, 2006, and is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to a communication terminal, a method for sendingcommunication data, a conference server device and a method forforwarding communication data.

BACKGROUND OF THE INVENTION

It is desirable to avoid unnecessary data traffic in the course oftelecommunication conferences. By way of example, it is desirable toreduce the data traffic in the course of a telecommunication conferenceprovided by means of a mobile radio network on the air interface.

SUMMARY

In line with one exemplary embodiment of the invention, a communicationterminal is provided which has an input device configured to inputcommunication data needing to be sent in the course of atelecommunication conference into the communication terminal, and amemory configured to store the input communication data. Thecommunication terminal also has a reception device configured to receivefrom a conference control server unit a message signalling that at leastone further communication terminal is ready to receive the communicationdata, a transmission device configured to operate in a first mode, inwhich it sends data at a first data rate, and in a second mode, in whichit sends data at a second data rate, the second data rate being higherthan the first data rate, and a control device which, following receiptof the message, is configured to control the transmission device suchthat the transmission device sends the communication data in the secondmode.

BRIEF DESCRIPTION OF THE FIGURES

Exemplary embodiments of the invention are illustrated in the figuresand are explained in more detail below.

FIG. 1 shows a communication system based on an exemplary embodiment ofthe invention.

FIG. 2 shows a data flowchart based on an exemplary embodiment of theinvention.

FIG. 3 shows a communication terminal based on an exemplary embodimentof the invention.

DETAILED DESCRIPTION

In the course of conference communication services, a plurality ofparticipants in a conference are permitted to communicate with oneanother using communication terminals.

So that orderly communication in the course of a conference is possible,typically not all the participants in the conference simultaneously havethe right to communicate, that is to say to send audio messages (or elsevideo messages etc.) to the other conference participants. Thecommunication right, that is to say the right to communicate, isallocated to the conference participants according to particular rules.This allocation is called “floor control”. The rules are called the“floor policy”.

In the case of communication systems in large conference rooms, that isto say in the case of permanently installed conference communicationsystems, the conference participants are provided with microphones andloudspeakers for voice communication. So that a conference participantcan transmit an audio message to the other conference participants, theconference participant's microphone needs to have been activated in thiscase. Typically, when one microphone is activated, all the othermicrophones are disabled, that is to say that what is spoken into theother microphones is not output by means of the loudspeakers. In somecases, another microphone is also activated, for example that of theconference head.

In mobile radio communication systems, communication services are knownwhich, like a conference communication system in a conference room orlike communication by means of walkie talkies, allow only thetransmission of audio messages from a single participant to the otherconference participants at any time. These communication services areknown by the name Push-To-Talk (PTT), such as the communication service“Direct Connect”, which is provided by the company Nextel in the USA,and the communication service PoC (Push to Talk over Cellular), which isspecified by the OMA (Open Mobile Alliance).

In similar fashion to the conference communication system describedabove which is used in a conference room, a conference participant usingPTT needs to press a special key, typically on his mobile radiosubscriber terminal, so that he is permitted to transmit audio messages.During the transmission of audio messages from this conferenceparticipant, the transmission of audio messages from other conferenceparticipants is disabled, that is to say that other conferenceparticipants are not permitted to transmit audio messages to conferenceparticipants.

In conference communication systems as proposed by the IETF (InternetEngineering Task Force), the allocation of the communication right iscontrolled by means of the BFCP (Binary Floor Control Protocol). Incurrent PTT communication systems, that is to say in communicationsystems which are used to provide a Push-To-Talk communication service,the communication right is requested and allocated using the RTCP (RealTime Control Protocol). In this case too, the allocation of thecommunication right may alternatively be controlled by means of BFCP.

It is also customary for the participants in a conference to be able tobe informed about the state of the conference by means of notification.By way of example, the participants can be notified of which participantis requesting the communication right for a particular medium (audio,video etc.). Notifications are implemented in conference communicationsystems, as proposed by the IETF, on the basis of the SIP (SessionInitiation Protocol). In current PTT communication systems, RTCP is usedto notify the participants about which of the participants is beingallocated the communication right.

A user of a PTT communication system, that is to say of a communicationsystem which is used to provide a PTT communication service, can be aparticipant of a plurality of PTT sessions at the same time.

If a user is a participant in a plurality of PTT sessions then hestipulates one of the PTT sessions as a primary session. The otherinstances of the PTT sessions are stipulated as secondary PTT sessions.If other participants send communication data (audio data, video dataetc.) both in a secondary PTT session and in a primary PTT session inwhich the user is participating then only the communication data sent inthe course of the primary PTT session are forwarded to the participant.Only if no communication data are sent by other participants in thecourse of the primary PTT session communication data which are sent inthe course of a secondary PTT session are forwarded to the participant.

So that it may be ensured that the communication data sent by aparticipant can also be received by at least one further participant,typical PTT communication systems involve the communication right beingallocated to the participant in the course of a PTT session only if atleast one further participant is participating in the PTT session andhas confirmed that he is receiving communication data sent in the courseof the PTT session. This can result in delays in the allocation ofcommunication rights when a PTT session is started.

When a participant joins a PTT session, he receives only communicationdata which have been sent in the course of the PTT session after hejoined the PTT session in the course of the PTT session. Similarly, itmay occur that a participant in a PTT session misses communication datasent in the course of the PTT session, that is to say does not receivethem, since the PTT session is a secondary PTT session for theparticipant and communication data are sent in the course of a primaryPTT session for the participant.

In line with one exemplary embodiment of the invention, a communicationterminal is provided which has an input device, which can be used toinput communication data needing to be sent in the course of atelecommunication conference into the communication terminal, and amemory which stores the input communication data. The communicationterminal also has a reception device which receives from a conferencecontrol server unit a message signalling that at least one furthercommunication terminal is ready to receive the communication data, atransmission device which can be operated in a first mode, in which itsends data at a first data rate, and in a second mode, in which it sendsdata at a second data rate, the second data rate being higher than thefirst data rate, and a control device which, following receipt of themessage, controls the transmission device such that the transmissiondevice sends the communication data in the second mode.

In line with further exemplary embodiments of the invention, aconference server device and a method for forwarding communication datain accordance with the communication terminal are provided.

In line with one exemplary embodiment of the invention, a method forsending communication data is provided in which communication dataneeding to be sent in the course of a telecommunication conference areinput into a communication terminal, the input communication data arestored, a message is received which signals that at least one furthercommunication terminal is ready to receive the communication data,following receipt of the message a transmission device, which can beoperated in a first mode, in which it sends data at a first data rate,and in a second mode, in which it sends data at a second data rate, thesecond data rate being higher than the first data rate, is controlledsuch that it sends the communication data in the second mode.

The message is received from a conference control unit, for example.

The following exemplary embodiments of the invention, which aredescribed in connection with the communication terminal, also applymutatis mutandis to the method for sending communication data, to theconference server device and to the method for forwarding communicationdata.

Sending the communication data input into the communication terminalprovided in the second mode, in which data are sent at a higher datarate, allows the communication data to be sent only when it is certainthat a further communication terminal is ready to receive thecommunication data. A possible delay (for example of several seconds)between the start of input of the communication data and sending of thecommunication data can be compensated for, since the communication dataare sent at an increased data rate and sending the communication datacan therefore catch up with input of the communication data, forexample.

By way of example, the first data rate is the data rate which isrequired and usually used in order to transmit the communication data tothe further communication terminal in real time at a prescribed quality.If the communication data are audio data, for example, then the firstdata rate is the data rate which is required to transmit the audio datato the further communication terminal at a prescribed quality, so thatthe audio data are available in the further communication terminal atthe prescribed quality and can be output only delayed in time by delayswhich arise as a result of transmitting the audio data and encoding anddecoding the audio data at the same speed at which they were spoken intothe communication terminal.

By way of example, real-time data transmission of communication data isto be understood to mean that the receiver of the communication dataperceives the output of the received communication data as though theyhad been transmitted by the transmitter and originator of thecommunication data, for example the speaker of audio data, without anydelay.

The second data rate is a data rate which is higher than the first datarate, for example a data rate increased by 25%, 50%, 75% or 100% ormore. Accordingly, in the case of audio data, the audio data can betransmitted to the further communication terminal quickly enough forthem to be available there at the prescribed quality and for them to beable to be output at a higher speed. This therefore means that theperson listening to the audio data is also able to catch up with thespeaking of the audio data when the audio data have begun to be spokenbefore the audio data have begun to be sent, for example several secondsbeforehand, for example 3 seconds, 7 seconds or 10 seconds.

An advantage of one exemplary embodiment of the invention is that thesending of audio data does not need to be started until it is actuallycertain that a further communication terminal is ready to receive thecommunication data. By way of example, the communication data can berejected if there is a relatively long period of time during which nofurther communication terminal is ready to receive the inputcommunication data. By way of example, the communication terminal maycontain a timer which measures the length of time between the start ofinput of the communication data and receipt of the message. If thelength of time exceeds a prescribed threshold value, the process can beterminated and the communication data can be erased. It is alsopossible, by way of example, to ask the user whether it is necessary tocontinue waiting until the message is received or whether the processshould be terminated.

This has the advantage that the communication data are sent only if theycan actually be received by a party to the communication. This makes itpossible to avoid unnecessary data traffic. If the communicationterminal is a mobile radio subscriber appliance then the unnecessarytransmission of communication data can be avoided on the air interfacebetween the communication terminal and the relevant base station in themobile radio communication system.

The effect achieved by this is that a user can start to inputcommunication data immediately and, by way of example, does not need towait for confirmation that he is being granted the communication rightor a further user is participating in the telecommunication conferencewithout communication data being sent unnecessarily and, by way ofexample, an air interface being burdened unnecessarily.

The control device in the communication terminal described above cancontrol the transmission device such that it sends a further messagespecifying that the telecommunication conference needs to be set up.

In one embodiment, the control device controls the transmission devicesuch that it does not send any communication data needing to be sent inthe course of the telecommunication conference between the time at whichthe further message is sent and the time at which the message isreceived.

Thus, first communication data are not sent until the communicationterminal has been notified that a further communication terminal isready to receive the communication data. However, even before thecommunication data are sent, it is possible to start inputting thecommunication data into the communication terminal using the inputdevice.

By way of example, the input device can be used to input thecommunication data as soon as the further message has been sent.

In line with one exemplary embodiment of the invention, inputcommunication data are not sent immediately but rather are buffer-storedfirst. Buffer-storage is to be understood to mean buffer-storage whichtakes place before the buffer-storage carried out in the course ofchannel encoding or during buffering in the course of data transmission,for example.

By way of example, the message specifies that at least the furthercommunication terminal is participating in the telecommunicationconference.

The communication data are audio data, video data, image data or textdata, for example. The telecommunication conference is a Push-To-Talkconference, for example.

By way of example, the communication terminal is a mobile radiosubscriber appliance. Accordingly, the communication between thecommunication terminal and the conference control unit and the sendingof the communication data are effected via the air interface of a mobileradio communication network, for example. In other words, thetelecommunication conference is carried out using a mobile radiocommunication network. Alternatively, the telecommunication conferencecan be provided by means of a landline network. The telecommunicationconference can also be provided by means of the Internet, for example,and the communication terminal may accordingly be an appliance withInternet Protocol capability which is coupled to the Internet.

By way of example, the mobile radio communication network is a mobileradio network based on the UMTS (Universal Mobile TelecommunicationsSystem) standard, based on the GSM (General System for MobileCommunications) standard or based on the CDMA 2000 standard (CDMA: CodeDivision Multiple Access).

FIG. 1 shows a communication system 100 based on an exemplary embodimentof the invention.

The communication system 100 can be used to provide PTT conferences fora plurality of users. A first user uses a first communication terminal101, a second user uses a second communication terminal 102, a thirduser uses a third communication terminal 103, a fourth user uses afourth communication terminal 104, a fifth user uses a fifthcommunication terminal 105, a sixth user uses a sixth communicationterminal 106 and a seventh user uses a seventh communication terminal107.

The first communication terminal 101 is coupled to a first controlserver unit 109 (controlling function) by means of a first participantserver unit (participating function) 108, the second communicationterminal 102 is coupled to the first control server unit 109 by means ofa second participant server unit 110, the third communication terminal103 is coupled to the first control server unit 109 by means of a thirdparticipant server unit 111, the fourth communication terminal 104 iscoupled to the first control server unit 109 by means of a fourthparticipant server unit 112, the fifth communication terminal 105 iscoupled to a second control server unit 114 by means of a fifthparticipant server unit 113, the sixth communication terminal 106 iscoupled to the second control server unit 114 by means of a sixthparticipant server unit 115, and the seventh communication terminal 107is coupled to the second control server unit 114 by means of a seventhparticipant server unit 116.

The first participant server unit 108, the second participant serverunit 110, the third participant server unit 111 and the fourthparticipant server unit 112 and also the first control server unit 109are implemented by means of a first PTT (Push-To-Talk) server computer117. The fifth participant server unit 113, the sixth participant serverunit 115, the seventh participant server unit 116 and the second controlserver unit 114 are implemented by means of a second PTT server computer118.

A control server unit has functionalities which are associated with thePTT session, that is to say the conference. A participant server unithas functionalities which are associated with the participant who isassociated with the participant server unit. A participant server unitwhich is associated with a participant can therefore be considered partof the communication terminal used by the participant in order toparticipate in the conference. In the case of a mobile communicationsystem, however, the participant server unit is arranged in thenon-mobile part of the communication system.

A control server unit and a participant server unit associated with theparticipant in the PTT session can be implemented by different PTTserver computers. By way of example, this is the case when the PTTsession has been generated by means of a communication network which isnot the home network of the participant. In this case, the participantserver unit is implemented by means of a PTT server computer belongingto his own network operator, that is to say the operator of theparticipant's home network. By contrast, the control server unit for thePTT session is implemented by means of a PTT server computer belongingto the alien network operator, that is to say the network operator ofthe communication network which has been used to generate the PTTsession. In the course of the PTT session, the participant communicatesusing a communication link between the PTT server computer belonging tohis own network operator and the PTT server computer belonging to thealien network operator.

First of all, it is assumed that the first control server unit 109 isnot yet providing a PTT session, that is to say is not yet providing aPush-To-Talk conference. In addition, in a first exemplary embodiment itis assumed that the second control server unit 114 is also not yetproviding a PTT session.

In the exemplary embodiment explained below, it is also assumed that theuser of the second communication terminal 102 wishes to initiate a PTTsession using the first control server unit 109. The participants in thePTT session initiated by the user of the second communication terminal102 will be the user of the first communication terminal 101, the userof the third communication terminal 103 and the user of the fourthcommunication terminal 104.

The corresponding flow of data and the sequence are shown in FIG. 2 andare explained below.

FIG. 2 shows a data flowchart 200 based on an exemplary embodiment ofthe invention.

The flow of data occurs between a first communication terminal 201, asecond communication terminal 202, a third communication terminal 203, afourth communication terminal 204 and a control server unit 205, whichare designed and arranged as explained with reference to FIG. 1.

The user of the second communication terminal 202 wishes, as mentioned,to initiate a PTT session which is provided by means of the controlserver unit 205, which corresponds to the first control server unit 109in FIG. 1, and in which the first communication terminal 201, the secondcommunication terminal 202, the third communication terminal 203 and thefourth communication terminal 204 participate.

To this end, the second communication terminal 202 transmits acommunication right request message 207 to the control server unit 205in step 206. The communication right request message 207 is used by thesecond communication terminal 202 to request from the control serverunit 205 that the control server unit 205 provide a PTT session whichthe first communication terminal 201, the third communication terminal203 and the fourth communication terminal 204 are invited to join. Inaddition, the second communication terminal 202 uses the communicationright request message 207 to request the communication right, that is tosay the right to transmit communication data in the course of the PTTsession which is to be set up by the control server unit 205.

In line with the communication right request message, the control serverunit 205 transmits a respective invitation message 211 to the firstcommunication terminal 201, the third communication terminal 203 and thefourth communication terminal 204 in steps 208, 209 and 210. Theinvitation messages 211 are used to ask the first communication terminal201, the third communication terminal 203 and the fourth communicationterminal 204 to join the PTT session which is provided by the controlserver unit 205 in line with the communication right request message207.

At the same time as the communication right request message 207 is sentin step 206, the user of the second communication terminal 202 starts tospeak audio data 212 into the second communication terminal 202. By wayof example, the user of the second communication terminal 202 speaksinto a microphone which is provided on or in the second communicationterminal 202 while simultaneously pressing a special key, for example aPTT key, which is provided on the second communication terminal 202. Theaudio data 212 spoken by the user of the second communication terminal202 are buffer-stored in the second communication terminal 202 using amemory in the second communication terminal 202.

In this exemplary embodiment, the user of the second communicationterminal 202 speaks only audio data 212 into the second communicationterminal 202, but in other embodiments he can also input text data orvideo data into the second communication terminal 202. By way ofexample, video data can be input using a digital camera with which thesecond communication terminal 202 is equipped.

When a certain period of time has elapsed, as indicated by the dasheddouble-headed arrow 213 in FIG. 2, the user of the first communicationterminal 201 is ready to join the PTT session provided by the controlserver unit 205 in line with the communication right request message207. Accordingly, the first communication terminal 201 transmits ajoining message 215 to the control server unit 205 in step 214, saidjoining message being used to indicate that the first communicationterminal 201 is joining the PTT session. The control server unit 205then adds the first communication terminal 201 to the PTT session as aparticipant and in step 216 transmits a notification message 217 to thesecond communication terminal 202, said message being used to signalthat the first communication terminal 201 has joined the PTT session.

The second communication terminal 202 therefore now knows that at leastone participant is participating in the PTT session, namely the user ofthe first communication terminal 201. The second communication terminal202 then converts the audio data 212 which have already been spoken andare currently being spoken by the user of the second communicationterminal 202 into a bit stream 218, for example using suitable encodingof audio data, for example encoding based on an MPEG (Moving PicturesExpert Group) standard. The bit stream 218 is continuously transmittedto the control server unit 205 for as long as audio data 212 are beingspoken into the second communication terminal 202 by the user of thesecond communication terminal 202 in step 219. The control server unit205 receives the bit stream 218 as a received bit stream 220.

The bit stream 218 is transmitted from the second communication terminal202 to the control server unit 205 at an increased bit stream data rate.That is to say that the bit stream data rate which is used to transmitthe bit stream 218 is higher than the data rate required for real-timedata transmission of the audio data 212.

This means that it is possible for the transmission of the bit stream218 to catch up with the speaking of the audio data 212, for example.That is to say that, although the audio data 212 have already begun tobe spoken when the communication right request message 207 was sent, butthe bit stream 218 does not begin to be transmitted to the controlserver unit 205 until after receipt of the notification message 217, itis possible that all the audio data 212 which have already been spokenat the time at which speaking of the audio data 212 is ended, which isindicated by the dashed line 221, have already been converted into thebit stream 218 and have been transmitted to the control server unit 205.The transmission of the bit stream 218 therefore catches up with thespeaking of the audio data 212 in the sense that after a particulartime, the time of catching up, the audio data 212 which are currentlybeing spoken are converted into the bit stream 218 and are transmittedto the control server unit 205.

So that the first communication terminal 201 is also provided with theoption of catching up with the speaking of the audio data 212 in asimilar manner, the received bit stream 220 is converted by the controlserver unit 205 into audio data 222 compressed in time. Thetime-compressed audio data 222 are compressed in time in comparison withthe audio data 212, that is to say that the sound sequence in the audiodata 212 is contained in the time-compressed audio data 222 at a higherspeed. If the user of the second communication terminal 202 has spoken asentence into the second communication terminal 202 within 10 seconds,for example, so that this sentence is now contained in the audio data212 with a record length of 10 seconds, then this sentence is containedin the time-compressed audio data 222 with the record length of 7seconds, for example, and would accordingly be output at an increasedspeaking speed in 7 seconds instead of in 10 seconds when thetime-compressed audio data 222 are output.

Compression in time is not to be understood to mean source encoding orchannel encoding, but rather condensing the audio data in time, in otherwords accelerating the sound sequence.

The time-compressed audio data 222 are converted by the control serverunit 205 into a bit stream of time-compressed audio data 223 which istransmitted to the first communication terminal 201 in step 224 and isavailable there as a received bit stream of time-compressed audio data225. The received bit stream of time-compressed audio data 225 istransformed back into the time-compressed audio data 222 by the firstcommunication terminal 201, and these data are output by means of aloudspeaker 226 on the first communication terminal 201.

Since the time-compressed audio data 222 are compressed in time incomparison with the audio data 212, it is possible that thetime-compressed audio data 222 in the first communication terminal 201have also been output (after any delay as a result of the transmissionsand conversions) to the user of the first communication terminal 201 infull at the time at which the speaking of the audio data 212 is ended,which is indicated by the dashed line 221, and that the output of theaudio data 212 has caught up with the speaking of the audio data 212 inthis sense.

In one embodiment, the bit stream of time-compressed audio data 223 istransmitted to the first communication terminal 201 at a normal datarate, that is to say the data rate required for real-time transmissionof audio data.

If the third communication terminal 203 or the fourth communicationterminal 204 joins the PTT session after the first communicationterminal 201, the time-compressed audio data 222 can be transmitted insimilar fashion to the third communication terminal 203 and to thefourth communication terminal 204. The time-compressed audio data 222can be compressed still further in time in line with the later joiningof the third communication terminal 203 and of the fourth communicationterminal 204, so that the third communication terminal 203 and thefourth communication terminal 204 also have the opportunity to catch upwith the speaking of the audio data 212.

Catching up is to be understood to mean that the time difference betweenthe time at which a word (or a sound) is spoken into the secondcommunication terminal and the time at which the word (or the sound) isoutput is reduced until it is so small that it now merely corresponds tothe delay which arises as a result of the encoding, decoding andtransmission of the spoken communication data.

At the time indicated by the dashed line 221, further audio data canimmediately be spoken and transmitted, for example by the user of thefirst communication terminal 201, in the course of the PTT sessionbecause the first communication terminal 201 and possibly the thirdcommunication terminal 203 or the fourth communication terminal 204 havecaught up with the speaking of the audio data 212.

In another embodiment, the first control server unit 109 provides afirst PTT session for the first communication terminal 101 and thesecond communication terminal 102 (or for the relevant users). Thesecond control server unit 114 provides a second PTT session for thefirst communication terminal 101, the fifth communication terminal 105,the sixth communication terminal 106 and the seventh communicationterminal 107 (or for the relevant users).

In the course of the first PTT session and the second PTT session, therespective participants send and receive communication data (mediadata). In this exemplary embodiment, communication in the course of thePTT sessions is by means of audio data.

The first communication terminal 101 participates both in the first PTTsession and in the second PTT session. In particular, a communicationlink 119 exists between the first participant server unit 108 and thesecond control server unit 114. It is assumed that the second PTTsession is stipulated as the primary PTT session and the first PTTsession is stipulated as a secondary PTT session. That is to say thatthe first participant server unit 108 forwards communication dataneeding to be transmitted to the first communication terminal 101 in thecourse of the first PTT session to the first communication terminal 101only if no communication data currently need to be forwarded to thefirst communication terminal in the course of the second PTT session.

If the user of the second communication terminal 102 wishes to send datain the course of the first PTT session then these data are received byanother user only if no communication data are currently beingtransmitted in the course of the second PTT session, since apart fromthe first communication terminal 101 and the second communicationterminal 102 no other participant is participating in the first PTTsession. In similar fashion to the exemplary embodiment described abovewith reference to FIG. 2, it is therefore not clear whether audio data(in general terms media data) spoken into the second communicationterminal 202 are being received by a receiver. In the exemplaryembodiment described with reference to FIG. 2, the reason for this isthat it is not certain whether another participant besides the secondcommunication terminal 202 will participate in the requested PTTsession. In the exemplary embodiment which is now being described, thereason is that it is not certain whether communication data which areinput into the second communication terminal 102 are being forwarded tothe first communication terminal 101, since communication data maycurrently be transmitted to the first communication terminal 101 in thecourse of the second PTT session.

The procedure in this exemplary embodiment is similar to that in theexemplary embodiment described with reference to FIG. 2. Instead of thecommunication right request message 207, a communication right requestmessage is transmitted to the first control server unit 109 and is usedto request the communication right for the second communication terminal102 in the course of the first PTT session. At the same time as thecommunication right request message is sent, the user of the secondcommunication terminal 102 starts to input the communication dataneeding to be sent in the course of the first PTT session, for exampleto speak audio data, in similar fashion to FIG. 2. The first controlserver unit 109 checks whether communication data are being transmittedto the first communication terminal 101 in the course of the second PTTsession, that is to say whether the first communication terminal 101 isready to receive the communication data.

As soon as the first communication terminal 101 is ready to receive thecommunication data input into the second communication terminal 102, anotification message is transmitted, in similar fashion to thenotification message 217, from the first control server unit 109 to thesecond communication terminal 202, signalling that the firstcommunication terminal 201 is ready to receive the communication datawhich have been input. The rest of the procedure is similar to theexemplary embodiment described with reference to FIG. 2.

In summary, in line with one exemplary embodiment, a communicationterminal is provided as shown in FIG. 3.

FIG. 3 shows a communication terminal 300 based on an exemplaryembodiment of the invention.

The communication terminal has an input device 301 which can be used toinput communication data 302 needing to be sent in the course of atelecommunication conference into the communication terminal 300. Thecommunication terminal 300 also has a memory 303 which is set up tostore the input communication data 302 and also a reception device 304which is set up to receive from a conference control server unit 305 amessage 306 signalling that at least one further communication terminalis ready to receive the communication data.

A transmission device 307 in the communication terminal 300 can beoperated in a first mode, in which it sends data at a first data rate,and in a second mode, in which it sends data at a second data rate, thesecond data rate being higher than the first data rate. Thecommunication terminal 300 also has a control device 308 which is set upto control the transmission device 307, following receipt of the message306, such that the transmission device 307 sends the communication data302 to a receiver 309 in the second mode. By way of example, thereceiver is the further communication terminal, which is ready toreceive the communication data. The receiver may also be a server unit,for example a participant server unit, or the conference control unit305, which is set up to forward the communication data to the furthercommunication terminal which is ready to receive the communication data.

In line with one exemplary embodiment of the invention, a communicationterminal is provided which has an input device which can be used toinput communication data needing to be sent in the course of atelecommunication conference into the communication terminal, a memorywhich stores the input communication data, a reception device whichreceives from a conference control server unit a message signalling thatat least one further communication terminal is ready to receive thecommunication data, a transmission device which can be operated in afirst mode, in which it sends data at a first data rate, and in a secondmode, in which it sends data at a second data rate, the second data ratebeing higher than the first data rate, and a control device which,following receipt of the message, controls the transmission device suchthat the transmission device sends the communication data in the secondmode.

In line with one exemplary embodiment of the invention, a communicationterminal is provided which has an input device which can be used toinput communication data needing to be sent in the course of atelecommunication conference into the communication terminal, a memorywhich stores the input communication data, and a reception device whichreceives from a conference control server unit a message signalling thatat least one further communication terminal is ready to receive thecommunication data. The communication terminal also has a transmissiondevice and also a control device which controls the transmission device,following receipt of the message, such that the transmission devicesends the communication data at a data rate which is higher than thedata rate required for real-time data transmission of the communicationdata.

In line with another exemplary embodiment, a communication terminal isprovided which has an input device which can be used to inputcommunication data needing to be sent in the course of atelecommunication conference into the communication terminal, and amemory which stores the input communication data. The communicationterminal also has a transmission device which can be operated in a firstmode, in which it sends data at a first data rate, and in a second mode,in which it sends data at a second data rate, the second data rate beinghigher than the first data rate, and a control device which controls thetransmission device such that it sends a first message specifying thatthe telecommunication conference needs to be set up. The communicationterminal also has a reception device which receives from a conferencecontrol server unit a message signalling that at least one furthercommunication terminal is ready to receive the communication data. Thecontrol device controls the transmission device such that it does notsend any communication data needing to be sent in the course of thetelecommunication conference between the time at which the furthermessage is sent and the time at which the message is received, and thecontrol device controls the transmission device, following receipt ofthe message, such that the transmission device sends the communicationdata in the second mode.

1. A communication terminal comprising: an input device configured toinput communication data needing to be sent in the course of atelecommunication conference into the communication terminal; a memoryconfigured to store the input communication data; a reception deviceconfigured to receive from a conference control server unit a messagesignalling that at least one further communication terminal is ready toreceive the communication data; a transmission device configured tooperate in a first mode, in which it sends data at a first data rate,and in a second mode, in which it sends data at a second data rate, thesecond data rate being higher than the first data rate; and a controldevice, following receipt of the message, configured to control thetransmission device such that the transmission device sends thecommunication data in the second mode.
 2. The communication terminalaccording to claim 1, wherein the control device is configured tocontrol the transmission device such that it sends a further messagespecifying that the telecommunication conference needs to be set up. 3.The communication terminal according to claim 2, wherein the controldevice is configured to control the transmission device such that itdoes not send any communication data needing to be sent in the course ofthe telecommunication conference between the time at which the furthermessage is sent and the time at which the message is received.
 4. Thecommunication terminal according to claim 1, wherein the input device isconfigured to input the communication data as soon as the furthermessage has been sent.
 5. The communication terminal according to claim1, wherein the message specifies that at least the further communicationterminal is participating in the telecommunication conference.
 6. Thecommunication terminal according to claim 1, wherein the communicationdata is at least one of audio data, video data, image data and textdata.
 7. The communication terminal according to claim 1, wherein thetelecommunication conference is a Push-To-Talk conference.
 8. Thecommunication terminal according to claim 1, wherein the communicationterminal is a mobile radio subscriber appliance.
 9. A method for sendingcommunication data, comprising: inputting communication data needing tobe sent in the course of a telecommunication conference into acommunication terminal; storing the input communication data; receivinga message which signals that at least one further communication terminalis ready to receive the communication data; and controlling, followingreceipt of the message, a transmission device, which can be operated ina first mode, in which it sends data at a first data rate, and in asecond mode, in which it sends data at a second data rate, the seconddata rate being higher than the first data rate, such that it sends thecommunication data in the second mode.
 10. The method for sendingcommunication data according to claim 9, wherein the message is receivedfrom a conference control unit.
 11. A conference server devicecomprising: a message generation device configured to generate a messagesignalling that at least one further communication terminal is ready toreceive communication data stored in a communication terminal; atransmission device configured to send the message to the communicationterminal; a reception device configured to operate in a first mode, inwhich it receives data at a first data rate, and in a second mode, inwhich it receives data at a second data rate, the second data rate beinghigher than the first data rate; and a control device, when the messagehas been sent, configured to control the reception device such that thereception device receives the communication data in the second mode.